Ebene und räumliche nichtlineare Berechnungen im Tunnelbau am Beispiel aktueller und geplanter Baumaßnahmen

Plane and three-dimensional analysis in tunneling using the example of current and planned construction

If the soil cover above an existing tunnel is significantly reduced due to additional construction measures or if additional large loads are introduced it is often necessary to perform a three dimensional analysis. While modeling soil or rock non linear material laws are typically employed. For economic reasons linear elastic material laws should be applied for the tunnel lining.If a linear analysis in combination with modifications to the existing structure does not provide a sufficient level of safety of the overall system a non-linear analysis approach may be an useful alternative for the design of tunnel linings. Non-linear analysis of tunnel linings is required for unreinforced inner tunnel linings or in cases of significant local removal of the soil cover of existing tunnel structures. For such cases this paper outlines how a non-linear analysis can be structured and how the necessary load increments should be considered in the soil-tunnel FE model to correctly reflect the bearing behavior of the soil.